Tumbler switch



May 14, i957 o. LEUTHOLD 2,792,464

TUMBLER SWITCH Filed Jan. 25, 1954 .the contact.

VThe present invention relates toa tumbler switch which represents a further development of the tumbler switch accordinf7 to the United States-patent,applicatioxnSerial No. 269,454, now abandoned,of-which the instant application is a continuation-impart, and incorporatesia beam carried by at least oney supporting member-.in a rocking bearing in which it can tilt, said beam serving` to operate `a switching rocker.

if such a switch is used for comparatively big. switching capacities, especially in view of the heavy initial currents arising in the loading with tungsten lamps, it may happen that-thecontact elements weld together. Then the force ofthe springotherwise causing .the tilting of the switching rocker `is no longer suicient tok open The primary objectV of the present invention is, therefore, to providega tumbler switch in which ,the Contact can be opened even if the contact` elements .may perchance be welded together.

.The tumbler switch according to .the present invention is essentially. .characterized in that theV switching rocker has at least one actuating lug which-projects into the path of motion of anl associated cam of the beam and, upon actuation of the beamat least for opening said Contact, comes up against the cam and then positively initiates movement of the switching rocker if the latter has not been previously tilted into its otherswitching position.

It is, therefore, another object of thepresent invention to provide means affording a simplified, yet, highly efficient tumbler switch structure which may be easily and positively operated at all times, even when the contact elements thereof tend to adhere to one another.

it is still another object of the present invention to provide means conducive to novel and improved tumbler switches which are extremely sturdy and compact in construction but may be operated with a minimum of eort and with a minimum of noise.

A further object of the present invention is to provide means presenting eiective and durable tumbler switches which are economically vmanufactured from a minimum number of parts, may be easily installed, and require no additional maintenance after installation.

Preferably, the design is such that the cam can only come up against the actuating lug when the beam has made more than haii of the motion it requires for actuating the switch, i. e., when the beam has been pivoted past its dead center position. The beam may also include two cams which, when said beam moves in one way or the other, may cooperate with the actuating lug or lugs of the switching rocker in order to positively start tilting movement of the latter.

The invention will be fully and comprehensively understood from a consideration of the following detailed description when read in connection with the accompanying rawing which forms part of the application, lwith the understanding, however, that the improvement is capable of extended application and is not confined to fice *theexactshowing 'of vthe drawing nor to the precise con struction described and, therefore, such changes -and 'modifications-may be made therein'as do not atfect the vspirit of the invention nor exceed the scope thereof as expressed in the appended claims.

In the drawing: Fig l is a side view of-a tumbler switch according to vrthe invention with closed contact, the insulatingbase being shown in section;

Fig. 2 is a sectional view of the tumbler switchembodying the invention, the viewfbeing .taken along line II-.Iliof Fig. 1;

Fig. 3 is a partial longitudinal. sectional View of the `samecswitchl withv opened contact, vthis `view being taken along line III-.III of'Figl;

Fig. Bashowsa detailzaccordingto Fig. 3, :and Fig. Suis a representation similar to Fig. 3v showing weldedcontact elements, and illustratingthe opening mo- 'tionv and function of'l the operating beam.

' has twoupright lugs substantially parallel to each other,

into each of which two V-shapedynotches are cutV from below and from above, respectively, which serve as rocking bearings ofithe knife-edge type. The operating beam 17 has two projections 19 which, as supporting members, engage in the upwardlyV opening bearing notches. From Fig l it maybe seenthat supporting members 19 at their free ends, and also the associated bearing notches, have cylindrical surfaces cooperating with each other and sliding on each other when beam 17 tilts. Each supporting member 19 is provided with a flange 2t? which extends past Athe associatedbearing lug, preferably along the side thereof turned to the other bearing lug, thus preventing lateral displacement of operating beam 17 in the direction of its tilting axis. Beam 17, supporting members 19, and tianges 20 may; if desired, be formed from one single piece Yof insulating material.

Switching rocker 1S engages with its shoulders 18a in the downwardly opening notches of bearing member 16 and `is resiliently connected to beam 17 by tension spring 2l. One end of said tension spring 2i' engages a lug or crossbar 22 of the switching rocker, said lug being provided with a concave knife-edge 22a, and the other end of the spring is attached to a cross-pin 23 of the beam. The spring is locatedbetween the two supporting mem- 'bers i9 and/or flanges 2i? of the beam. The free end of rocker 18 carries Ya contactelement 24 which cooperates with a stationary contact element 2S seated on a leaf spring 26. For connecting the electric wires to the switch, provision is made for terminal screws 27 and 2d, the iirst of them being connected to leaf spring 26, and the second of them by means of a connecting rail 2g to bearing member 16 and thus to rocker 1%.

On each flange 20 there are provided two projections or cams 30 and 31 with a groove 32 formed therebetween, as more clearly shown in Fig. 4. Switching rockerl includes two actuating lugs 33, each of which extends into one of said grooves 32 and between which tension spring 21 is arranged. The width of groove 32 is, however, appreciably greater thanthe thickness of actuating lugs' 33, so that each of these has a great amountl of play in its associated groove. From the above disclosure and from the drawing it may be realized that both actuating lugs 33 and also the associated cams 30 and 31 are mon beam.

located in close proximity of the bearing centers of switching rocker 1S and/or of beam 17.

It will further be seen that the rocker 1S consists of a rst portion extending rearwardly from the lugs 33 and shoulders 18a, e, g. the right-hand portion as seen in Fig. l, and of a second portion bent over and forwardly from the rearmost point of said rst portion of the rocker, whereby the contact element 24 is carried at the free and foremost end of said bent over rocker portion and thus is located substantially at the same level as the lower bearing surface of the bearing member 16 against which the shoulders 18a of the rocker 18 adjacent the lugs 33 abut.

"Suchran arrangement enables the switch assembly as an entity to be constructed with a minimum overall height, i. e., front to rear dimension,which is especiallyladvantageous where the entire switch assembly is to be located exteriorly of the wall or other'surface designed to support said switch assembly. Moreover, the arrangement of the rocker 18 makes it possible to locate the contact element 25 closer to the upper or front surface of the switch assembly, whereby access to the contact element 25 and to the associated terminal screw 27 for purposes of repair, adjustment and the like is -greatly facilitated.

When operating beam 17 is tilted out of the position shown in Fig. l into that illustrated in Fig. 3, switching rocker 18 springs from the closed into the open position by action of tension spring 21. In the open position as in Fig. 3, the rocker abuts against a bent-over lug 34 (Fig. 2) of bearing member 16. If beam 17 swings in the other direction, rocker 1S again moves into the closed position as in Fig. 1, where the two contact elements 24 and 25 are engaging each other.

lf contact elements 24 and 25 were to become welded together in consequence of a big initial current, the pull of spring 2l would not be suicient to open the contacts when the beam is brought into the position shown in Fig. 3. But during the movement of the beam in the direction for opening contact 24/25, cam 30 of each flange 20 comes up against the associated actuating lug Y 33 of switching rocker 18, since said lugs project into the paths of motion of the cams. This position is shown in Fig. 4. lf beam 17 is now pressed further in the direction of arrow P into the position as in Fig. 3, a torque in the sense of opening contact 24./ 25 will positively be exerted by cams 3Q on actuating lugs 33. In this way the weld connection between contact elements 24 and 25 can be loosened and tilting movement of switching rocker 18 positively started, whereupon the pull of spring 21 suddenly moves the rocker into the open position.

lt is understood that the tumbler switch could also be designed as a change-over switch by arranging a second leaf spring with a second stationary contact element in such a way that the contact element on the switching rocker engages said second stationary contact element on being tilted upwards. In this case lug 34, acting as stop, can be omitted. In the case of a change-over switch, it is possible that the switching rocker becomes firmly welded either when tilted downwards or upwards. If the latter is the case, upon actuation of beam 17 the cams 30 or 31 come up against actuating lugs 33 of rocker 1S, whereupon the tilting movement of the switching rocker can be effected positively. The cams 3i) and 31 are so arranged that they can only cooperate with the associated actuating lug 33 whenever the beam has passed through at least half of its movement required for operating the switch. Obviously, cams Si) and 31 only come up against the associated actuating lugs 35 of the switching rocker if Vthe latter has n ot been previously tilted into the other switching position.

Alternatively, the tumbler switch could also be designed as intermediate switch or as two-pole switch.l This needs two electrically separate, similar switching systems arranged parallel beside each other and operated by a com- Should the switch according to the present invention be employed in a circuit where it would never be subjected to high currents or current surges, the cams 30/31 could be omitted. Finally, it would also be possible to provide only one single actuating lug cooperating with a single cam on the beam, or with two cams in the case of a change-over switch.

As compared with the switches describedinrthe abovementioned parent application, the switches disclosed hereinbefore have the advantage that any contact weldings perchance occurring cannot Vdisable the action of the switch, and that the contact can always be positively opened. f l

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

l. A tumbler switch comprising a base of insulating material, an electrically conductive bearing member mounted on said base and having front and rear faces provided, respectively, with first and second bearing notches arranged opposite one another, an operating beam of insulating material provided with projection means engaging in said first bearing notches, whereby said beam is tiltably supported on said front face'of said bearing member, a switching rocker provided with a rst portion having front and rear ends and having shoulder means at said front end engaging in said second notches of said bearing member on the rear face thereof for rocking movement of said rocker relative to said bearing member, said rocker further being provided with a second portion extending forwardly of said base from said rear end of said first portion and having a rst contact element fixed thereto at the foremost part of said second portion, resilient means connected at one end to said operating beam and at another end to said switching rocker adjacent the junction of said first and second portions and operable to retain both said beam and said rocker on said bearing member, at least one pair of cams on said beam, said cams being spaced from one another in a direction transverse to the tilting axis of said beam to form a recess, at least one actuating lug on said rst portion of said rocker and projecting into said recess, and a second contact element stationarily mounted on said base and engageable by said irst contact element, whereby said resilient means alone normally causes said rocker to be rocked upon tilting movement of said beam, said cams being operable to engage said actuating lug and initiate rocking movement of Vsaid rocker only upon failure of said resilient means to initiate said rocking movement.

2. A tumbler switch comprising a base of insulating material, a bearing member on said base and having front and rear surfaces, operating means of insulating material supported on said front surface of said'bearing member for rocking movement about a first axis, a switching rocker comprising lirst and second portions arranged at an acute angle with respect to one another with one end of said iirstvportion being in' contact with said rear surface of said bearing member for rocking movement of said roclrer about a second axis substantially parallel to said first axis, a contact element on that end of said "e" y ond portion of said rocker remote from said one end of said 'irst portion and movabletherewith, Vthe lengths of said first and second portions being predetermined to dispose said movable contact element in substantially co- `and engageable by said movable contact element, said Vresilient means alone normally being operable to roel;

said rocker about said second axis upon rocking move ment of said operating'means about said rst axis, said dream4 cam means when moving in said path being operable to apply force to said actuating means and initiate rocking movement of said rocker only upon failure of said resilient means to initiate said rocking movement due to binding of said contact elements.

3. In a tumbler switch having a base of insulating material and a xed contact element thereon; the combination of a bearing member on said base and having front and rear surfaces, at least said rear surface of said bearing member being electrically conductive, with operating means pivotally engaging said front surface or said bearing member, electrically conductive rocker means engaging said rear surface of said bearing member for rocking movement relative thereto about an axis parallel to the axis of pivotal movement of said operating means, a movable contact element connected to said rocker means at a location substantially coplanar with said rear surface of said bearing member and engageable with said xed contact element in one position of said rocker means, spring means connected to both said operating means and said rocker means and biasing both the latter and said operating means into engagement with said front and rear surfaces of said bearing member, respectively, said spring means alone normally being operable to inpart rocking movement to said rocker means upon pivotal movement of said operating means on said bearing member, and cooperable means on said operating means and on said rocker means and adapted to abut one against the other only upon failure of said spring means to cause said rocking movement due to binding of said contact elements, thereby applying positive contact opening forces to said rocker means.

4. The combination according to claim 3, said cooperable means comprising cam means on said operating means and actuating means on said rocker means, said actuating means being disposed within the path of movement of said cam means.

5. The combination according to claim 3, said cooperable means comprising cam members on said operating means spaced from one another substantially transversely of said axis of pivotal movement of said operating means and defining a recess, and at least one actuating lug on said rocker means projecting into said recess.

6. The combination according to claim 3, said cooperable means comprising at least two cam members on said operating means and spaced from one another in a direction substantially parallel to said axis of pivotal movement of said operating means, and at least two actuating lugs on said rocker means, said lugs projecting, respectively, into the paths of movement of said cam members as said operating means moves from its closed- Contact position to its open-contact position.

7. The combination according to claim 6, said spring means having one portion connected to said operating means intermediate said cam members and having another portion connected to said rocker means intermediate said actuating lugs.

8. The combination according to claim 6, said cam members being located in close proximity to said axis of pivotal movement of said operating means, and said actuating lugs being located in close proximity to the rocking axis of said rocker means.

9. The combination according to claim 6, said cooperable means further comprising two additional cam members on said operating means, said additional cam members being spaced from one another in a direction substantially parallel to said axis of pivotal movement of said operating means and being spaced from said rstnamed cam members, respectively, in a direction substantially transverse to said axis of pivotal movement of said operating means, whereby a recess is defined between each of said first-named cam members and the corresponding one of said additional cam members, said lugs projecting into said recesses, respectively.

10. The combination according to claim 9, said rocker means comprising first and second portions extending substantially lengthwise of one another and each having opposite front and rear ends, said front end of said first portion engaging said rear surface of said bearing member, said rear end of said rst portion being joined to said rear end of said second portion, said movable contact element being connected to said front end of said second portion, and the length of said second portion being predetermined to dispose said movable contact element in substantially coplanar relationship with said rear surface of said bearing member.

References Cited in the file of this patent UNITED STATES PATENTS 1,733,267 Kellner Oct. 29, 1929 1,777,525 Meuer Oct. 7, 1930 1,845,510 Murad Feb. 16, 1932 2,534,007 Dietrich Dec. 12, 1950 

